1. Field of the Invention
The present invention relates to an erasable electrophotographic toner containing an organic white pigment and a method of producing the same.
2. Description of the Related Art
Jpn. Pat. Appln. KOKAI Publication Nos. 05-61247 and 2000-19770 suggest a process for erasing with heat or light a print which is obtained by forming an image on a copying machine or printer using an erasable toner with an erasable leuco dye or a near-infrared light responsive erasable photosensitive toner, and thereby recycling paper. An image forming apparatus for the process comprises an erasing unit for toners inside or outside of the apparatus. In the case when the content of printed paper on which printing has been conducted by using a photosensitive toner becomes unnecessary, the paper is first subjected to erasing at the erasing unit of the apparatus to return the paper to a printable state, thereby the paper can be used again.
For erasing a letter or the like printed on paper, it is sufficient to erase the color of a toner that forms the letter, which is performed by subjecting the paper to erasing by a certain kind of process. According to the current needs, complete erasing with saved energy and on high-speed on demand is required. In order to meet these requirements, it is necessary that a toner has high erasability and superior visibility after erasing, in other words, the color difference between the color of an image after erasing and the color of base paper is reduced.
However, conventional photosensitive toners had a defect that the pre-erasing printed information can be recognized after erasing since the erasing is insufficient, and thus a shade remains or yellowing occurs after erasing. In such cases, recycling of paper may be interfered, or the pre-erasing information may be restored easily to cause leakage of information.